Improvement in ship-building



N. PETERS. FHOTGALITHCGRAPHER, WASHlNGTON. D C.l

UNITED STATES PATENT OFFICE.

JOHN W. GRIFFTHS, OF BROOKLYN, NEV YORK.

IMPROVEMENT IN SHIP-BUILDING.

Specification forming part of Letters Patent No. 34,360, dated February 11, 1862.

To all whom, it may concern:

Be it known that I, JOHN W. GRIEEITHs, of the city of Brooklyn, in the State of New York, haveinvented a certain new and useful Improvement on Ships and other Navigable Vessels, which I denominate a Ballast-Dispenser and Roll-Adjuster; and I do hereby declare the following to be a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters and marks thereon.

An assurance of stability in the design for a flotative structure ranks as one of the first considerations. A vessel at sea is unprolitable, uncomfortable, and to some extent dangerous with a precarious amount of practical stability being propelled on her side, in which position she not only makes much leeway, but is liable to be thrown on her beams-end in a beam-sea when the wind is most favorable for acquiring speed. Scarcely less so is a vessel having a redundancy of practical stability, being subject to quick rolling motion and sudden jerks when the wind and sea are on the beam. It is to obviate both of these difficulties that this invention is introduced, and by transposing the timber material from the inside of the bilge of wooden vessels, called bilge-keelsons, used for the purpose of giv- .ing strength to this Weak part, the capacity of the hold is increased, and by placing them on the outside of the bilge the strength is maintained and the draft of Water reduced, and the channel-ways between these keelsons thus formed serve as regulators to the rolling motion at sea by increasing the stability of vessels which are Wanting in that quality. because the buoyancy is increased Where it is required' and where by the formation of the bilge it has been reduced and the leeway increased. On the other hand, where the vessel has by increased breadth or by a low center of gravity of cargo been subjected to quick roll, the result of too great amount of practical stability, these longitudinal channel-ways between the outside bilge-keelsons serve as governors to increase and govern the time and number of rolls. The same is applicable to iron vessels, in which case the sheets of iron on the bilge will be of angleiron, the number, size, and longitudinal extent thereof being determined by the Want or extent ofthe vessels stability. On wooden vessels the channel-ways may be formed by increased thickness of plank at the bilge midships on alternate strokes, or by heavier timbers, as keelsons, substituted for planks and taking the place of planking strokes midships, and being thinned down to the planking thickness both forward and aft of midships, Where the bilge commences losing its quickness and its radius is increased.

The drawing forming part of this specification represents the midships body of avessel with the bilge-keelsons ct b c forming two channel-ways d c.

The number and size of the keelsons or channel-ways are not arbitrary, but may be dertermined as the requirements of the vessel may seem to demand, either to increase the strength of the vessel, prevent leeway, prevent deep or quick rolling, or to increase the capacity.

What I claim as my invention, and desire to secure by Letters Patent, is

The projecting bilge strokes or keelsons on the outside of ships and other navigable vessels, forming rectangular channel-ways, substantially as and for the purposes herein described.

JOHN VV. GRIFFITH.

Witnesses:

T. T. EVERETT, JOHN S. I-IoLLnvGsHEAD. 

